Associations between serum health biomarker concentrations and reproductive performance, accounting for milk yield, in pasture-based Holstein cows in southeastern Australia.

In this single cohort study, we investigated associations between the concentrations of a suite of serum biomarkers measured in the first 30 d of lactation and subsequent reproductive performance measured as mating start date to conception intervals, in pasture-based Holstein cows. A secondary objective was to examine associations between biomarker concentrations and 305-d milk yield to assess whether any positive associations between biomarker concentration and reproductive performance were explained by reduced milk production. The data used had been collected as part of an ongoing project from 2017 to 2020 to compile a data set from a large population of lactating dairy cows. Biomarkers measured were those associated with energy balance (ß-hydroxybutyrate [BHB] and nonesterified fatty acids [NEFA]), protein nutritional status (urea and albumin), immune status (globulin, albumin to globulin ratio and haptoglobin), and macromineral status (calcium and magnesium). Associations between biomarker concentrations and mating start date to conception interval were investigated using Cox proportional hazard models, using between 634 and 1,121 lactations (varying by biomarker) from 632 to 1,103 cows and 11 to 17 mating periods from 10 to 13 herds. Based on hazard ratio (HR) estimates and associated 95% confidence intervals (CI), hazard of conception on any particular day of the herds' mating periods was positively associated with the concentrations of albumin (HR = 1.09; 95% CI: 1.05-1.12), albumin to globulin ratio (HR = 2.82; 95% CI: 1.66-4.79), calcium (HR = 2.01; 95% CI: 1.18-3.43), and magnesium (HR = 2.17; 95% CI: 1.01-4.66), and negatively associated with globulin concentration (HR = 0.98; 95% CI: 0.97 to 1.00). There was also some evidence that NEFA concentration was negatively associated (HR = 0.76; 95% CI: 0.57 to 1.01), and urea concentration positively associated (HR = 1.05; 95% CI: 0.99 to 1.11), with reproductive performance, but no evidence that BHB and haptoglobin concentrations were associated with reproductive performance. Except for NEFA, presence and direction of the associations between the biomarker and milk yield were not discordant with that for reproductive performance. Also, except for NEFA, we found no substantial evidence of nonlinear relationships between biomarker concentration and either reproductive performance or milk yield. Correlations between biomarker concentrations were generally weak, indicating that multibiomarker panels may collectively predict reproductive performance better than any single biomarker. We noted substantial variation in the concentrations of all biomarkers within, and for some biomarkers, between herd-year groups. Collectively, these results indicate that there may be scope to improve biomarker concentrations through nutritional, management, and genetic interventions, and by association, reproductive performance and milk yield may also improve.

Milk production of cows grazing pasture supplemented with grain mixes containing canola meal or corn grain or both over the first 100 days of lactation.

Grain mixes varying in proportions of wheat grain, barley grain, canola meal, and corn grain were fed to grazing dairy cows in early lactation to determine the contribution of canola meal and corn grain to milk yield, BW, BCS, eating behavior, and blood serum metabolite concentrations. The experiment used 80 multiparous, seasonally calving Holstein-Friesian dairy cows during the first 100 d of lactation, the treatment period, and over the subsequent carryover period of 100 d, during which all cows were fed a common diet. Cows were divided into 4 cohorts (blocks) based on calving date and within each cohort, 5 cows were randomly allocated to each of the 4 treatments. Dietary treatments included disc-milled grain mixes comprising (on a DM basis) (1) a control treatment of wheat (25%) and barley (75%); (2) wheat (25%), barley (50%), and canola meal (25%); (3) wheat (25%), barley (50%), and corn (25%), and (4) wheat (25%), barley (25%), canola meal (25%), and corn (25%). Treatment diets were introduced at 19 DIM ± 4.7 d, which included a 7-d adaptation period and were applied up until 100 DIM. Each grain mix was fed at 9 kg of DM/cow per day, offered twice daily, in equal proportions in the parlor at milking times. In addition to the grain mix, all cows grazed perennial ryegrass pasture at a daily allowance of ∼35 kg of DM/cow per day (measured to ground level). Results were analyzed in terms of corn and canola presence or absence in the diet. Including canola meal in grain mixes increased grain intake and pasture intake by 0.6 and 2.1 kg of DM/cow per day, respectively, resulting in an increased milk yield of 2.6 kg/cow per day during the first 100 d of lactation. Including canola meal also increased yields of milk fat and protein, and concentrations of milk fat, as well as increasing mean BW and BCS over the 100 d. The inclusion of canola meal in the grain mixes also resulted in greater blood serum BHB and urea concentrations, compared with feeding grain mixes that did not contain canola meal. The inclusion of corn grain provided no milk production benefits and did not change BW, BCS, or any feeding behavior variables. There were no carryover effects on milk production from either canola meal or corn grain after the treatment period. In summary, the results demonstrate that the provision of canola meal in grain mixes can improve milk production and increase mean BCS. Further, there are no benefits to milk yield when a proportion of barley is substituted for corn, in a wheat and barley grain mix fed to grazing dairy cows in early lactation. However, these results are dependent on the level of inclusion and the feeding system employed.

Macroprolactin screening in 464 patients with hyperprolactinaemia.

INTRODUCTION: Macroprolactinaemia is usually detected by polyethylene glycol (PEG) precipitation in clinical laboratories. Laboratory data on prolactin and macroprolactin screening by PEG precipitation in a tertiary hospital were reviewed in order to revise the local policy for reflex screening and reporting of macroprolactin in patients with hyperprolactinaemia. MATERIALS AND METHODS: Paired prolactin results from 464 patients before and after PEG precipitation, either requested by a clinician or performed as a reflex test, were retrieved and reviewed. RESULTS: Recovery of prolactin after PEG treatment was highly variable (3.7 to 97.7%). The distribution of prolactin recovery percentages after PEG precipitation in patients with true hyperprolactinaemia was markedly different from that in patients without true hyperprolactinaemia. The proportion of patients with true hyperprolactinaemia increased gradually with increasing pre-PEG prolactin concentrations; the reverse was true with macroprolactinaemia. Five patients (1.1%) were found to have co-existing macroprolactinaemia and true hyperprolactinaemia. CONCLUSION: Results from this retrospective study indicate that macroprolactinaemia is common and can be present even in patients with very high serum prolactin concentrations. There is no cut-off limit for pre-PEG serum prolactin concentration that can totally exclude macroprolactinaemia. Moreover, co-existence of true hyperprolactinaemia and macroprolactinaemia in the same patient is not a rare phenomenon. Post-PEG prolactin concentration and percentage recovery should be reported together to guide the interpretation and management of hyperprolactinaemia.

Genetic mutations in patients with possible familial hypercholesterolaemia in South East Scotland.

Familial hypercholesterolaemia (FH) is one of the most common genetic disorders in the general population. Genetic testing of this condition is increasingly available in the UK to confirm its diagnosis, but the strategies of genetic testing vary. In this pilot study, we sought to investigate whether a strategy that focuses on the low-density lipoprotein receptor (LDLR) and apolipoprotein B (APOB) genes can identify the majority of genetic variants in patients with possible FH in South East Scotland. Forty patients with a clinical diagnosis of possible FH according to the Simon Broome criteria were recruited in a lipid clinic serving South East Scotland. All 18 exons of the LDLR gene were sequenced and multiplex ligation probe amplification was performed to identify major deletions and duplications. Variants of the APOB gene at codon 3527 were investigated by direct sequencing. Genetic mutations were detected in 45% of the patients. Sixteen patients (40%) were found to have mutations in their LDLR gene, whereas two other patients (5%) were identified as heterozygous for the APOB variant commonly associated with FH (c.10580G>A; p.R3527Q). None of these genetic variants were detected in more than two patients. Multiple genetic mutations are associated with a clinical phenotype of FH in South East Scotland. A genetic testing strategy which focuses on a limited number of mutations is unlikely to confirm the diagnosis of FH in the majority of patients in this part of Scotland.

Analysis of prostate cancer association with four single-nucleotide polymorphisms from genome-wide studies and serum phyto-estrogen concentrations.

BACKGROUND: Both genetics and the environment are implicated as risk factors for prostate cancer (PCa). This population-based case-control study evaluated four single-nucleotide polymorphisms (SNPs) previously identified by genome-wide association studies to be associated with increased PCa susceptibility. Potential relationships between serum concentrations of phyto-estrogens and SNPs were also investigated. METHODS: Four SNPs (rs10993994, rs2660753, rs1016343 and rs6983267) were genotyped in 247 PCa patients, 125 BPH patients and 274 control men recruited in Scotland. Serum concentrations of the phyto-estrogens enterolactone, equol, genistein and daidzein were measured by isotope dilution gas chromatography-mass spectrometry. RESULTS: Increased PCa risk was associated with TT genotype of rs10993994 compared with CC and CT genotypes combined (odds ratio (OR)=1.87; 95% confidence interval (CI), 1.26-2.77). TT homozygotes who had low serum enterolactone concentrations (below median) were more likely to have PCa (OR=2.90; 95% CI, 1.28-6.57) than individuals with CC/CT genotype and high serum enterolactone concentrations (above median). PCa was not associated with the other three SNPs tested. CONCLUSIONS: PCa susceptibility was associated with TT genotype of SNP rs10993994 in this cohort of Scottish men and the increased risk of PCa was modified by serum enterolactone concentrations.

FGFR4 Gly388Arg polymorphism and prostate cancer risk in Scottish men.

Fibroblast growth factor receptor 4 (FGFR4), a member of the fibroblast growth receptor family, was recently reported to be more abundantly expressed in malignant than benign prostate cells. A single nucleotide polymorphism at position 388 of the FGFR4 amino-acid sequence results in the substitution of glycine (Gly) with arginine (Arg) and higher frequency of the ArgArg genotype was previously found in prostate cancer patients. DNA was extracted from the blood drawn from 399 prostate cancer patients, 150 BPH patients and 294 healthy community controls. Polymerase chain reaction was carried out and single nucleotide polymorphisms of FGFR4 were identified by restriction enzyme digestion. No overall association is detectable between the Arg allele and increased prostate cancer risk. Subgroup analysis shows a higher incidence of the heterozygous ArgGly genotype in cancer cases than in the combined group of BPH and controls (P<0.05); this difference is statistically significant between cancer and BPH patients but not between cancer cases and community controls. The single nucleotide polymorphism Gly(388)Arg in FGFR4 is not associated with increased risk of prostate cancer in Scottish men. This observation is in contrast with results from two previous studies conducted in the USA and Japan.